Re: [Groff] X in \A'X' isn't ignored - bug report?

[Steffen Nurpmeso]

Werner LEMBERG <address@hidden> wrote:
 |> Well exactly that was however the initial problem: while testing the
 |> manual of the MUA i maintain i got three occurrences of similar
 |> errors for \A'' on the result of a ".substring 0 1".
 |
 |Ouch :-)  Not having an `interned' representation can be advantageous,
 |but here it's definitely a problem...
 |
 |> Note how you cannot even say \A'\*[a]\*[b]', since the result seems
 |> to get expanded on the fly and breaks \A'' if that ends up as "\[".
 |> So this is anything but robust and as such defeats the sole purpose
 |> of \A''.
 |
 |Yes, it can't handle backslashes because they are always handled
 |before the request sees them.  Note that you want expansion of \*[...]
 |and \n[...], but at the same time you want that a solitary `\['
 |doesn't cause an error.  How shall this work?

Hmm, ok i see now what you mean.  I don't know the code in
question yet, but should i ever come up with a nice solution
i will open a regular ticket with a patch for groff(1), too (if
possible).

..I think i would implement such a thing by parsing the construct
and then recursively expanding the bounded content until no more
expansion is possible, finally checking the result: Since \A''
is ment to check if that final result is a valid identifier
i think (now that) i wouldn't care wether \[ is "something
incomplete" in other contexts.  As above.

 |I can imagine to add another escape sequence (or request) that accepts
 |a string register as an argument, checking its contents.  Cf. the
 |`dei' request.

That would be another solution.  I'm just looking at ChangeLog.117
right now, but don't understand the complexity behind the problem
yet (what i hope).  That'll take time.  And as above. :)
Thanks, Ciao, and have a nice weekend..

--steffen